Seattle startup CityBldr has raised $4.3 million of a $4.5 million round, according to a new filing with the SEC. CityBldr founder Bryan Copley confirmed that he signed the SEC filing Wednesday morning but declined to comment further on the funding.

CityBldr’s software finds under-utilized land that could be developed into more lucrative properties. The company has helped neighbors with single-family homes that could support multi-family apartment buildings sell together as a bundle for greater returns than if they’d sold individually.

In June, CityBldr announced it would start buying some of those properties directly, rather than acting as an intermediary between sellers and developers. Less than a month later, Copley told GeekWire CityBldr plans to immediately open another office in the city selected for Amazon’s second headquarters. CityBldr currently has offices in Seattle and Los Angeles.

At the time, Copley said CityBldr was fundraising to support its growth plans. A month ago, CityBldr hired a chief investment officer to oversee its property buying business. The company is also raising a separate $100 million property investment fund to cover the costs of buying properties directly. CityBldr had raised $2.9 million before the latest funding.

Monica Nickelsburg is GeekWire’s Civic Editor, covering technology-driven solutions to urban challenges and the intersection of tech and politics. Before joining GeekWire, she worked for The Week, Forbes, and NBC. Monica holds a BA in journalism and history from New York University. Follow her @mnickelsburg